Expressions of love and affection

1- hit if off: Mary and Tom met  at a party last week and hit it off.
2- on the rocks. (no va muy bien, y quizá la relación está a punto de romperse)
My relationship with my husband is on the rocks.
3- pop the question. (proponer a alguien matrimonio)
I really love my girlfriend and I will pop  the question.
4- tie the knot. (get married)
Last week by friend and his girlfriend tied the knot.
5- fall head over heels.- (fall in love) We fell head over heels for each other.
6- puppy love- (not that serious). Don't worry, it's only puppy love.
7-  to settle down.- When are you going to settle down? (casarte y asentar la cabeza)